The subject matter disclosed herein relates to a steam turbine nozzle assembly, or diaphragm stage. Specifically, the subject matter disclosed herein relates to an austenitic segment design for a steam turbine nozzle assembly.
Steam turbines include static nozzle assemblies that direct flow of a working fluid into turbine buckets connected to a rotating rotor. The nozzle construction (including a plurality of nozzles, or “airfoils”) is sometimes referred to as a “diaphragm” or “nozzle assembly stage.” Steam turbine diaphragms include two halves, which are assembled around the rotor, creating horizontal joints between these two halves. Each turbine diaphragm stage is vertically supported by support bars, support lugs or support screws on each side of the diaphragm at the respective horizontal joints. The horizontal joints of the diaphragm also correspond to horizontal joints of the turbine casing, which surrounds the steam turbine diaphragm.